All Publications

Abstract

The insula is involved in interoceptive processing, emotion awareness, and attention to salient stimuli. Research suggests that these functions are specific-albeit overlapping-within insula subdivisions. Additional studies also imply that sexual dimorphism and different rates of development occur within these subdivisions in youth. The purpose of this study was to examine potential insula subdivision structure differences in youth with PTSD symptoms as compared to controls and test sex as a moderator of these differences.Insula structure (volume, surface area, and thickness) was measured with structural magnetic resonance imaging (sMRI) and calculated using Freesurfer software. We compared insula structure across age- and sex-matched boys and girls with (30 with and 29 without) PTSD symptoms while also controlling for age and whole brain measurements.Differences were specific to the insula's anterior circular sulcus. Within this subregion, boys with PTSD symptoms demonstrated larger volume and surface area than control boys, while girls with PTSD symptoms demonstrated smaller volume and surface area than control girls.Findings indicate a potential neurobiological explanation for sex differences in youth with PTSD symptoms.

Abstract

The objective of our study was to examine the neurobiological support for an interoceptive sensory processing model of bulimia nervosa (BN). To do so, we conducted a systematic review of interoceptive sensory processing in BN, using the PRISMA guidelines. We searched PsychInfo, Pubmed, and Web of Knowledge databases to identify biological and behavioral studies that examine interoceptive detection in BN. After screening 390 articles for inclusion and conducting a quality assessment of articles that met inclusion criteria, we reviewed 41 articles. We found that global interoceptive sensory processing deficits may be present in BN. Specifically there is evidence of abnormal brain function, structure and connectivity in the interoceptive neural network, in addition to gastric and pain processing disturbances. These results suggest that there may be a neurobiological basis for global interoceptive sensory processing deficits in BN that remain after recovery. Data from taste and heart beat detection studies were inconclusive; some studies suggest interoceptive disturbances in these sensory domains. Discrepancies in findings appear to be due to methodological differences. In conclusion, interoceptive sensory processing deficits may directly contribute to and explain a variety of symptoms present in those with BN. Further examination of interoceptive sensory processing deficits could inform the development of treatments for those with BN.

Abstract

Self-report studies suggest that patients with bulimia nervosa (BN) evidence difficulties with interoceptive awareness. Indeed, interoceptive deficits may persist after recovery of BN and may be a biological trait that predisposes symptom development in BN. However, no studies to date have directly assessed interoceptive sensitivity, or accuracy in detecting and perceiving internal body cues, in patients with or recovered from BN. Nine women who had recovered from BN and 10 healthy control women completed the Heart Beat Perception Task (HBPT) in which individuals were required to estimate the number of heartbeats between intervals of time. Accuracy scores were compared between groups. Significant differences were found between the groups on the HBPT ((F1,19) = 7.78, p = .013, Cohen's d = 1.16) when controlling for age. These results suggest that deficits in interoceptive sensitivity are present in individuals recovered from BN. Thus interoceptive deficits may be one factor that bridges the gap between brain dysfunction and symptom presentation in BN.

Abstract

Weak central coherence-a tendency to process details at the expense of the gestalt-has been observed among adults with bulimia nervosa (BN) and is a potential candidate endophenotype for eating disorders (EDs). However, as BN behaviors typically onset during adolescence it is important to assess central coherence in this younger age group to determine whether the findings in adults are likely a result of BN or present earlier in the evolution of the disorder. This study examines whether the detail-oriented and fragmented cognitive inefficiency observed among adults with BN is observable among adolescents with shorter illness duration, relative to healthy controls.The Rey-Osterrieth Complex Figure Test (RCFT) was administered to a total of 47 adolescents with DSM5 BN, 42 with purging disorder (PD), and 25 healthy controls (HC). Performance on this measure was compared across the three groups.Those with BN and PD demonstrated significantly worse accuracy scores compared to controls in the copy and delayed recall condition with a moderate effect size. These findings were exacerbated when symptoms of BN increased.Poorer accuracy scores reflect a fragmented and piecemeal strategy that interferes with visual-spatial integration in BN spectrum disorders. This cognitive inefficiency likely contributes to broad difficulties in executive functioning in this population especially in the context of worsening bulimic symptoms. The findings of this study support the hypothesis that poor global integration may constitute a cognitive endophenotype for BN.

Abstract

Recent evidence raises the possibility that symptoms of anorexia nervosa (AN) could be related to impaired interoception. Pain is an interoceptive process with well-characterized neuroanatomical pathways that may overlap to a large degree with neural systems that may be dysregulated in individuals with AN, such as the insula.Functional magnetic resonance imaging (fMRI) was used to assess neural substrates of pain anticipation and processing in 10 healthy control women (CW) and 12 individuals recovered from AN (REC AN) in order to avoid the confounding effects of malnutrition. Painful heat stimuli were applied while different colors signaled the intensity of the upcoming stimuli.REC AN compared with CW showed greater activation within right anterior insula (rAI), dorsolateral prefrontal cortex (dlPFC) and cingulate during pain anticipation, and greater activation within dlPFC and decreased activation within posterior insula during painful stimulation. Greater anticipatory rAI activation correlated positively with alexithymic feelings in REC AN participants.REC AN showed a mismatch between anticipation and objective responses, suggesting altered integration and, possibly, disconnection between reported and actual interoceptive state. Alexithymia assessment provided additional evidence of an altered ability to accurately perceive bodily signals in women recovered from AN.

Abstract

Our objective is to determine whether quetiapine was superior to placebo in increasing weight or reducing core symptoms of anorexia nervosa as assessed by the Yale-Brown-Cornell Eating Disorder Scale and the Eating Disorder Inventory-2.Participants were randomised to 8 weeks of quetiapine or placebo.There are 21 participants who signed informed consent, 15 were randomised, 14 returned for at least one visit after receiving drug and 10 completed the study. There were no differences between drug and placebo in questionnaire scores, weight or measures of anxiety or depression.There was no difference between quetiapine and placebo on weight gain or core symptoms. Small effect sizes suggest that a higher number of participants would not increase significant differences between groups.

Abstract

No studies have compared the response to selective serotonin reuptake inhibitors and atypical antipsychotics in anorexia nervosa. This case study examines such a comparison.This report describes a case of 12-year-old identical twins with anorexia nervosa, one of whom was treated with olanzapine and the other with fluoxetine, while undergoing family therapy.Twin A treated with fluoxetine went from 75 to 84.4% ideal body weight, while Twin B treated with olanzapine went from 72 to 99.9% ideal body weight over the course of 9 months.This case supports the need for adequately powered, controlled clinical trials to test the efficacy of olanzapine in adolescents presenting with anorexia nervosa.